Are Social Apps Necessary? (Twitter, Facebook,etc.)

I have a Droid X and with its built in Social Status and Social Network apps, is downloading an external Twiter and Facebook app necessary, or can you do all the things in the built in app you could with the external app.

I got a text with an @Reply from twitter and couldnt figure out how to see it through Droids built in social network app, so im assuming it is necessary to download the additional Social networking apps.

I think you've just alerted me to the reason I'm suddenly getting several unsolicited Voicemails and invitations to be "friends" - all this from people I don't know and/or from anonymous sources. This is a big pain. I've tried to delete these apps, but I haven't found a way to do it.